Titanium oxide (TiO2)/polyacrylic acid (PAA) composite nanotubes were firstly fabricated through the sol-gel process of titanium alkoxide in the inner pores of alumina template followed layer-by-layer assembly with polyacrylic acid (PAA). Mesoporous TiO2 nanotubes could be obtained after the removal of PAA component by calcination and etching of the template with concentrated sodium hydroxide aqueous solution. The surface area of as-prepared porous TiO2 nanotubes was measured as twice larger than that of the conventional TiO2 nanotubes and the pore diameter in the wall of the tubes is several nanometers. Such assembled mesoporous nanotubes can serve as carriers for catalysis release and biomolecules.